| What makes a server a server are the services that it offers. Does your department need a Web server? An e-mail server? FTP? To make the classroom work, it will need several services running all the time, but you do not want all of the standard services that Red Hat installs by default. To see what services your server has running, issue the following command: ps aux You will see a list of services scroll by. Notice that there are quite a few, and many of them are not necessary and are even risky to have running. In order to begin to turn services off or on depending upon our need, issue the following command: chkconfig --list A list of about two dozen services scrolls with the following format: syslog 0:off 1:off 2:on 3:on 4:on 5:on 6:off
crond 0:off 1:off 2:on 3:on 4:on 5:on 6:off The first word represents the name of the service. The numbers are the various runlevels of the machine. Since your server is running on level 3, you will be interested in the column “3:on/off.” To turn a service on or off, issue this command: chkconfig --level # name on|off For example, to turn the syslog service off (not that you should), you would enter: chkconfig –-level 3 syslog off The following services should be turned off if they are not already: xfs, amd, apmd, arpwatch, named, gpm, innd, irda, isdn, pcmcia, kdcrotate, mars-nwe, postgresql, rstatd, rusersd, rwalld, rwhod, snmpd, and rhnsd. These services should be turned on, if they are not already: syslog, crond, netfs, network, random, rawdevices, reconfig, anacron, atd, keytable, ipchains, kudzu, linuxconf, lpd, nfs, nfslock, ssh, identd, portmap, ypbind, yppasswdd, and ypserv. The services xinetd, httpd, and sendmail will be on or off depending on whether or not you want ftp services, web services, or mail services, respectively. Since these services are not necessary for our classroom server, I will turn them off: chkconfig –-level 3 xinetd off
chkconfig –-level 3 httpd off
chkconfig –-level 3 sendmail off Now the next time you reboot your machine, the services that you turned on and off should be that way. Don’t reboot yet, however; you still have some more configuring to do. Before installing various packages, you will want to download and install a helper program called wget. This program will allow subsequent downloads much easier. First, we have to get the package; type each line when presented with a prompt: ftp ftp.gnu.org
cd pub/gnu/wget
get wget-1.7.tar.gz
quit The above commands connected you with a remote server, and downloaded the wget tarball via FTP (file transfer protocol). The tarball is a basic Unix package of software source code that is both archived (.tar) and zipped (.gz). To uncompress and unarchive the software so that you can use it, type: gunzip wget-1.7.tar.gz
tar xf wget-1.7.tar
cd wget-1.7 The last command, cd, changes your directory so that you are now able to work with the software. In order for the source code to work with your system, it must first be set up, or configured, with the particulars of your system. These three commands will accomplish this: ./configure
make
make install Both the ./configure and make commands will take a moment to complete. Once all three have finished, you can test your new program by typing: wget And you should get the following output: Usage: wget [OPTION]... [URL]...
Try `wget --help’ for more options. Now, you are ready to begin configuring your system’s services, beginning with the printer. |